Evaluation of the effect of extra-amniotic normal saline infusion alone or in combination with dexamethasone for the induction of labor

Abstract

Aim: To compare the effect of extra-amniotic normal saline solution infusion on its own, and in combination with dexamethasone on the ripening of the cervix and induction of labor.

Methods: A double-blind randomized clinical trial study was performed at Akbar Abadi Teaching Hospital in Tehran, Iran, between March 2002 and March 2003 on 84 pregnant women at a gestational age of 40 weeks or more, and with a Bishop score <or= 5 with cephalic presentation, singleton pregnancy and intact membranes who had been admitted in the labor ward for the induction of labor. The women were randomly assigned into the two groups. In 41 cases, dexamethasone 20 mg extra-ovulary, plus extra-amniotic saline solution infusion (EASI) was prescribed, and in 43 patients EASI alone was prescribed. After 6 h of these protocols, oxytocin was started. Following this the process of labor up to delivery was followed in the two groups and a comparison was made.

Results: There were no statistically significant differences between the two groups according to age, parity, gravidity and primary Bishop score. Of the 84 women, 75 entered the active phase of labor (38 [88.37%] in the EASI group and 37 [90.25%] in combined group) without a significant difference. The duration between oxytocin infusion until delivery were 7.25+/-2.86 h and 9.76+/-3.91 h in the dexamethasone and EASI groups, respectively, which showed a statistically significant difference (P=0.002). There were no significant differences between the two groups according to cesarean section rate, meconium passage by fetus, neonatal Apgar score, birthweight, and need for the neonatal intensive care unit. There was a statistically significant negative correlation between gravidity and interval between oxytocin induction and delivery (P=0.001, r= -474).

Conclusion: Extra-amniotic saline solution infusion is a suitable and cheaper method for the ripening of the cervix and induction of labor, and adding the dexamethasone to it can shorten the duration of labor without any significant risk to the mother or her fetus.